Drying machine



3 SHEETS-SHEET l.

VEN TDR;

G. STONE.

DRYING MACHINE. Y

muted July 4, 1922,

APPLICATION FILED' DEC. I5. 192|.

G. STONE.

DRYING MACHINE. APPLICATION FILED DEC.f5, 192|.

'lAfn21856 Patented July 4, 1922.

3 SHEETS--SHEET 2.

/A/vE/v TUR.' IW W32@ G. STONE. DRYING MACHINE. APPLICATloN FILED DEc.l5, 1921.

rnuraosraras- Parana canoa,

GEORGE STONE, VOF NORTH ANDOVER, MASSACHUSETTS, ASSIGNOR OF ONE-HALF T0 lill. T. STEVENS & SONS COMPANY, OF NORTH ANDOVEB., MASSACHUSETTS, A CORf- PORATION OF MASSACHUSETTS.

DB'YING MACHINE.

Specification of Letters Patent.

Patented July 4L, 1922.

Application filed December 15, 1921. Serial No. 522,491.

To all whom z5 may concern.'

Be it known that I, GEORGE STONE, a citizen of the United States, residing at North Andover, in the county of Essex and State o f Massachusetts, have invented new and useful Improvements in Dryin Machines, of which the following is a specifi-cation.

This invention relates to machines for drying material, such as washed wool, by passing the same in a sinuous course, and in a plurality of horizontal stretches through a casing, from the upper to the lower portion of the latter, and forcing hot air through the horizontal stretches while they are being conveyed, the said stretches being conveyed by horizontal rows of rolls arranged at di'erent heights, and spaced apart to, provide air passages through which hot air is forced between the rolls, the arrangement being such that each row above the lowest, drops' the material on,to a ylower row, the rolls of each row rotating in unison, in a direction opposite that of the next` row. l

One object of the invention is to provide means for conducting independent currents of hot air under the rolls of each row, and causing a forcible upward discharge of. air between the rolls in such manner as to not only pass through and dry the conveyed material, but also to lift the same and prevent it fromv clinging to the rolls and clogging the latter.

Another object is' to enable hot air that has been discharged between the rolls of one row, and has once performed its function, to be again utilized by cooperating with the rolls of another row or rows, and to be repeatedly heated without being discharged from the machine, thus economizing heat. v

Another object is to provide means for highly heating the air supplied to the lower rows of the series, so that. foreign matter in the material conveyed by said rows may be carbonized.

Another Objectis to provide means for crushing carbonized matter delivered by the lower" row of rolls.

The invention is embodied in the improvements hereinafter described and claimed.

' Of the accompanying drawings forming a part of this specilication,-

Figure 1 is a side elevation of a drying mach-ine embodying the invention.

Figure 9 is an enlargement of a'portion of Y y Figure 1. v

Figure l0 is a top plan view, showing portions of the crushing rolls shown by dotted lines in .Figure 9, and the mechanism for driving the lower rolls.

vFigure l1 is a view similar to Figure 9, omitting the mechanism for driving the lower crushing rolls.

Figure 12 is a section on line 12-12 o Figure 10. A

TheA same reference characters indicate the same parts in all of the figures.

The casing 12 of the machine, which may be of any suitable construction, is formed to house the various rolls and air conductors hereinafter described, and is provided at its upper portion with an inlet 13, to which materialv to be dried is fed by any suitable means.v As shown by Figures`1 and 4, the feeding means may includean endless conveyor 15.- Within the casing is aplurality of horizontal rows ofv rolls 16, the rolls of each rowl being spaced apart, as bestshown by Figure 5, to form air spaces 17 between the rolls, and rotated in unison tol convey material from end to end of the row. Each row above the lowest is arranged to drop the material conveyed'by it on to a lower row, and the rolls of each row are rotated in a direction opposite that of the rolls or the neXt row, `so that the rolls are adapted to conduct the ceiving ends of the rows by fixed guides or 4 deflectors 19. Any suitable mechanism may be provided for rotating the rolls, suc-h as sprocket wheels 2()- (Figures 2, 3, and 8),

portions of which Vare shown in detail by Figures 2 and 3, the chains being shown conventionally and in dotted lines by Figure 1. The general construction and arrangementA thus far described is well known, ,and does not of itselfy form va part of my invention.V

f I do not, therefore, fully show the sprocket chains, nor the mechanism that'drives the same, it being suicient to say that the chains may be driven bypower impartedrthrough a driving-shaft, indicated at 23 (Flg'ure '1), horizontal stretches of the chains being engaged with the sprocket wheels on the rolls to simultaneouslyrotate the rolls of each row in the directions described.

In, .accordance with my invention, vI provide air forcing and heating apparatus at one end'of the casing 12, and locate separate air conductors under the rows of rolls, communicating with said apparatus, and adapted independently to conduct air from the said apparatus under the rolls of each row, and to exhaust or discharge the conducted air upwardly through the spaces 17, between vthe rolls and into air chambers above the rolls. The air thus exhausted acts onthe'material in transit on the rolls, to not only dry the material by passing through it, but also to lift the `material suiciently to prevent it from clinging to the rolls, and therefore from being carried between and clogging the rolls, said independent conductors being the essence of the invention.

Each conductor is preferably. provided by locating in the casing below'each row of rolls a horizontal sheet metal bottom plate 24, extending from side to side of the casing, as indicated by Figures 6 land 7, and extending lengthwise of the casing from end lto end of the series of rolls above it, asshown4 by Figure 4, one end of. said plate being turned up into close proximity to the roll 16, at the delivery end of the row, to form a transverse end 4wall 25. The plate 24, the endwall -25,portions of the sides of the casing 12, and the row of rolls constitute a box which has an inlet communicating with the i air-forcing and heating apparatus, and a multiplicity of ,outlets provided by .the

spaces 17 between the rolls. -.Air forced under pressure into said box is forcibly exhausted or discharged through said spaces into material conveyed by the rolls, and lifts said material while drying it. The box thus constituted, and the rolls associated therewith, lmay be called a material-drying and conveying unit. The machine may include any desired number of units, five being here shown.

An air chamber is provided above each of from, 'said chambers being designated respectively 1, 2, 3, 4 and 5, at the right hand end portion of Figure 4, each chamber having an air outlet. The air exhausted into the highest chamber 1 is heavily charged with moisture, .andhas an air outlet 27 (Figurev 4) larranged to discharge the moist air into the atmosphere. The outlets f other air chambers maybeprovided by by-passes arranged to conduct the air that has performed its function in one unit to a lower portion of the machine, so that air that is not objectionably moist, and contains laconsiderable percentage of heat, may be again utilized without being discharged from the machine.

Referring to Figures 1, 4, 6, and 7, it will be seen that the air chamber 2 is connected by an angular by-pass 28 with Va horizontal return flue or passage 29, located between the third and fourth units, and that a branch 28.a of saidby-pass is connected with the air chamber 3. There are preferably two of said by-passes, one at each side of the casing 12. The return iue 29 communicates with said units, to receive the air exhausted therethe air-forcing and heating apparatus,

which is organized as hereinafter described, to exert suction on air in said iue, so that air is drawn from the chambers 2 and 3, and through the return flue to the said' apparatus, where Iit is additionally heated, and from whichvit is forced to units above the said flue, as indicated by some of the arrows in Figure 4. i

I have shown two units below the flue 29,

one exhausting into the chamber 4, and the other into the chamber 5. The airchamber 4 1s connected by a by-pass 31, with a lower horizontal return flue 32, located below the.

bottom unit, and by a branch 31ay of ,said bypass with the air chamber 5. The return flue 32 communicates with the air-forcing and heating apparatus,.which exerts suction on air in said flue, so that air is drawn from the chambers 4 and 5, and through the re-4 turn flue 32 to the said apparatus, where it is additionally heated, and from which it is forced into the air conductor of the lowest unit, as indicated by arrows in Figure 4.

The air-forcing and heating apparatus is preferably arranged to force air directly into the air conductor of the unit immedi-v ately under the chamber 1, through lan inlet 34 (Figure 4), and into the air conductor ,of the unit immediately under the chamber 3, through an outlet 35. A portion of the air forced by said apparatus into the conductor of the highest unit may enter t'he conductor of the next lower unit through a by-pass 36' (Figures 4 and G), the air exhausted from this unit into the chamber 2 being withdrawn therefrom through the bypass 28, as above described. Air isvpreferably forcedv by said apparatus into the air conductor ofthe lowest unit immediately reales@ under the chamber 5, through an inlet 37 (Figure 4), and is exhausted between the rolls of said unit into the chamber 5, from whence it is drawn to the return iue 32, as above described. A portion of the air forced by said apparatus into the conductor Lof the lowest unit, may enter the chamber of the next higher unit through a by-pass 36a (Figures-4 and 7), the air exhausted from this unit into the 'chamber 4 being withdrawn therefrom, and returned to the airforcing and heating apparatus.

When the machine is used for drying wool containing burrs, and other` vegetable foreign matter capable of being carbonized, I arrange the conveying and drying units in two groups, one above and the other below the return iue 29. I also provide an airforcing and heating apparatus, composed of two separate sections, one which is called the primary section, and is associated with the units of the upper group, and the other, which is called the secondary section, with the units of the lower group.

' As shown by Figure 4, the primary section includes an upper box or casing 38, and

` through the retur-n flue 32.

the secondary section includes a lower box or casing 39. In each casing is a fan adapted to draw air from some of the air chambers, and force the same into the air conductors of the corresponding units. Any suitable type of fan may be employed. I show only the casings 41 of said fans, each fan having an intake through which air exhausted from some of the units enters the casing, and an outlet through which air is forced ,through a heater and back to the units. The fan in the'casing 38 forces air between the pipes or coils of a steam heated radiator 42, located in said casing between the fan and the inlets 34 `and 35, and draws exhausted air through the return flue 29.

The fan in the secondary casing 39 forces air between the pipes or coils of a similar radiator 43, located between said fan and the inlet 37, and draws exhausted air It will now be seen thath the fan in the primary 'casin 38 forces air, through the upper group o ,units, and that the exhausted ot or warm air from said units, excepting that discharged into the atmosphere at the outlet 27, is drawn back into the primary casing by said fan.

It will also be seen that air is rapidly circulated through the heater 43, the Vunits of the secondary group and the return flue 32. A suiiiciently high temperature is therefore maintained in the unitsV of this group, to carbonize foreign matter in the conveyed material.

At the delivery end of the lower row of tively driven in unison with said lower rolls 16, and a series of vertically movable springpressed idle rolls 46. The material delivered by the lower rolls 16 passes between the rolls 45 and 46, and is subjected thereby to pressure sufficient to crush the carbonized material. The lower rolls 45 may be driven in unison by a suitable train of gears 48 (Figures 9, 10 and 1l), to which power is applied through a driving pulley 49. The crushing rolls are preferably located within the casing 12, and deliver the material through the outlet 18.

It is obvious that when material is to be dried without being carbonized, a smaller number of units may be employed, the Acrushing means being omitted, and the air-forcing and heating apparatus being suitably modified.

rIhe various by-passes may be provided with clean-out openings or hand holes, closed by removable covers 50, as shown by Figure l. rllhe casing 12 may bel provided with doorways, closed by doors 51. 'Ihe perforated sheet-,metal plates 52, shown by Figures 4, 6, and 7, in the chambers 2, 3, 4 and 5', are baffle-plates, which prevent the air discharged between the rolls 16 from taking the shortest possible path to the intakes of the several by-passes, so that the air lifts the material on the rolls more effectively than would be the case if said baiie-plates were not present.

'Ihe perforated plates also intercept lint, or small fragments of material rising from the rolls 16, and prevent the same from being, conducted to the fans. Each perforated plate is preferably made in sections, which are loosely supported in the casing 12, and are removable through the said doorways, lwhen the doors 51 are opened, so that they may be readily cleaned. The said hand holes are intended to permit the removal from the by-passes of lint, and like matter accumulating therein.

The crushing rolls 45 and 46 are of larger diameter than the conveying rolls 16,' and rotate at a greater surface velocity, the crushing vrolls being preferably about nine inches 1n diameter, while the diameter of the rolls 16 is preferably about three inches. To prevent the material from being drawn ,too rapidly from the delivering end of the lower row of rolls 16, by the crushing rolls, I provide a loose'idle holding-back roll 55 (Figure 4), arranged to'bear on material passing across the trough formed by the upper sides of the last two rolls 16 of the lower row. Said idle roll is preferably about six inches' in diameter, and it acts to partially hold back the material before it reaches the nip of the crushing rolls, by which it is first engaged, the fibers of the material being stretched between the holding-back roll and the nip of the first pair of crushing rolls, sor that it passes evenly, and not in bunches, between the crushing i rolls.

It will be seen by reference to Figure 4,

l that the air chamber 4 above the lower group .ondary section`39, of the air-forcing and heating apparatus, finds its way into the air chamber 3, and isutilized to dry materiall conveyed by the units of the upper group.

The casing sections 38v and 39'are closed against the admission of air, excepting through the return or suction flues 29 and 32, and against the out-How of. air, excepting through the outlets 34,` 35 and 37, so that air pressure is maintained in said sections by the fans.,v The intake of each fan casing may draw iny a limited volume of outside air through orifices 40 (Figures 1 and 4) in addition to the air drawn through the return or suction flues, but the volume of outsider air thus drawn in should be considerably less than that drawnl through said suction lues. When the machine is in operation, air is continuously forced through the primary heater 42, to the units and air chambers of the upper group, the air exhausted from the highest unit vescaping to the atmosphere, while ,the air exhausted from theother units of the upper group returns to the rimary section 38, through the upper suction flue 29, and is again heated by the heater 42. Air is also' continuously forced through the secondary heater 43 to the units and air chambers of the lower group, and returns to the secondary section 39 through the lower suction flue 32, and is again heated by the heater 43, this air being at a fairly high temperature and relatively dry, so that anyv sur plus 4thereof which may be caused to pass through the passage 56 (Figure 4), by pressure in the units and air chambers of the lower group, -is utilized to good advantage in the units and air chambers of the upper group It is obvious that the machine may be used for drying any fibrous material such as wool,

i air under the rolls of each row, the conducted air being exhausted or discharged upwardly through said spaces into air chambers above the rolls, and utilized to both dry companyin and lift material in transit on the rolls, each row of rolls and the accompanying conducf tor constituting a conveying andI drying unit. A

f 2. A drying-machine comprising a plurality of horizontal rows of conveying rolls arranged at different heights, and adapted to; conduct material' in av sinuous course through the machine, the rolls of each row being separated by air spaces; air-forcing and heating apparatus; independent air conductors under said rows 'connected with said apparatus and adapted independently to conduct air under the rolls of each row, the conducted air being exhausted -or discharged upwardly through said spaces into air chambers above the rolls, and utilized to both dry and' lift material inr transit on the rolls, and means including by-passes communicating with some of said air chambers, whereby air exhausted into an air chamber after performing its function isagain utilized.

3. A ldryin and carbonizing-machine comprising a p urality of horizontal rows of conveying rolls arranged at different heights, and adapted to conduct material in a sinuous course through the machine, the rolls of each row-being separated by air spaces; airforcing and heating apparatus; independent air conductors under said rows connected 95 with said apparatus and adapted independently to conduct air under the rolls of each row, the conducted air being exhausted or discharged u wardly through said spaces into air cham ers above the rolls, and utilized to both dry andlift material in transit on the rolls, each row of rolls and the acconductor constituting. a conveylng an drying unit, the said air forcing and heating apparatus being composed of a primary section, communicating with an upper group of said units, and any air circulatin secondary section, communicating with a ower,group, the arrangement being such that the lower group is heated to ,clarbonize foreign matter in material conveyed by the rolls thereof, and crushing rolls at the delivering end of the lower row of rolls for crushing such carbonized matter.

4. A drying and.. carbonizing-machine 115 substantially as specified by claim 3, -com- I prising also means adapted and arranged to conduct surplus heated air exhausted from the lower `group of units to the upper group.

5. A drying and carbonizing-machine substantially as specified by claim 3, com! prising also a return flue adapted to conduct heated Aairexhausted from the upper group of units to the saidvprimary section. 6. A drying and carbonizing-machine substantially as specified by claim 3, comprising also a return iue, adapted to 'con-- duct heated airwexhausted from the lower group Aof units, to the saidsecondary sec'- tion.

insiste 7. In a drying-machine, a conveying and drying unit comprising a horizontal row of conveying rolls, separated by air spaces, and rotated in unison to convey material from end to end of the row, and enclosing means under said row forming, with the latter, a box having air outlets formed by the spaces between the rolls, said enclosing means being adapted to receive air, and to exhaust the same through said outlets, so that material conveyed by the rolls is dried and also lifted to prevent it from clogging the rolls.

8. A drying-machine comprising a casing having an inlet and an outlet, aplurality of drying and conveying units located at diferent heights, and arranged to cause material to pass in a sinuous course from the inlet to the outlet, each unit including a row of rolls rotated in unison'and spaced apart, and an air. conductor under the rolls and adapted to discharge airupwardly between the rolls, the casing being provided with air chambers above said units into which air forced between the rolls is exhausted; air-forcing and heating apparatus; and connections between said apparatus and the said air conductors and air chambers, the arrangement being such that air is forced independently through the heating units and exhausted therefrom into the chambers.

9. A drying-machine comprising a casing having an inlet and an outlet, a plurality 'of drying and conveying units located at different heights, and arranged to cause material to pass in a sinuous course from the inlet to the outlet, each unit including a row of rolls rotated in unison and spaced apart, and an air conductor under the rolls and adapted to discharge air upwardly between the rolls, the casing being provided with air chambers above said units, into which air forced betweenfthe rolls is exhausted; the highest air chamber -being open to the atmosphere; air-forcing and heating apparatus; and circulating connections between said apparatus, the said air conductors and the lower air chambers, the arrangement being such that air is circulated through the heating units and through the lower chambers, and reheated at said apparatus.

.10. A drying-machine comprising a\ casing; air-forcing and heating apparatus; a plurality of horizontal conveying and drying units, arranged at di'erent heights in the casing and adapted to cause material Vto pass in a sinuous course through the casing, each unit including va row of spaced apart rolls, rotated in unison, and anindependent air conductor under the row, and communicating with the spaces between the rolls, the f casing being provided with a series of air chambers into which air is exhausted from said units to dry and lift material in transit; and air-conducting connections between said apparatus .and the said conductors and air chambers, whereby air is forced from the apparatus into the conductors, and returned to the apparatus from the air chambers.

ll. A drying-machine substantially as specied by claim 10, the said air-forcing and heating apparatus being composed of a primary section and a secondary section, the said units being arranged in an upper group and a lower group, and the said air-conducting connections being organized to return air lexhausted from units of the upper group to the said primary section, and to return air exhausted from the units of the lower group to the secondary section, to be heated by the latter for the ycarbonization of matter carried by material in transit on the rolls of the lower units.

12. A drying and carbonizing-machine substantially as specified by claim 3, an air chamber associated with the lower group of units, being connected with an air chamber associated with the upper group, so that sui-, plus heated air that has been utilized in the lower group is again utilized in group. y

13. A drying-machine substantially as specifiedby claim 2, comprising also perforated horizontal bafle-plates located in said air chambers, and adapted to prevent access of lint and other like matter to the air-forcing apparatus.

14. A drying and carbonizing machine substantially as specified by claim 3, comprising also a loose holding-back roll associated with conveying rolls at the delivering end of the lowest unit, and adapted to cooperate with said crushing rolls in stretching and evening fibers of the material in transit.

In testimony whereof I have aiiixed my signature.

GEORGE STONE.

the upper 

